Walking canes are well known to those with ordinary skill in the art. Walking canes include a cane consisting of a single stick held in one hand and providing stability when the user places the distal end on the ground in the direction of travel so that the stick provides a third point of contact with the ground as the user moves. Modern walking canes can be more complex, with three or four legs on a foot assembly (U.S. Pat. No. 4,044,784); allow for an adjustment of staff length (U.S. Pat. No. 4,085,763); or telescoping canes for easy storage when not in use (U.S. Pat. No. 3,987,807).
Without wishing to be bound by any particular theory, it is believed that multiple-leg canes attempt to provide stabilization by providing more than one point of contact with the ground. With two or more contacts, the cane is believed to be less likely to twist or turn than when a single point of contact is maintained. However, the success of these canes is limited because the points of contact must change during the gait. For example, a four-legged cane usually has only two of its legs in contact with the ground for most of a user's gait; the back two legs of a four-legged cane touch the ground when the user extends it out to take a step. As the user's center of gravity reaches the cane's contact points, all four legs are on the ground, and then as the user passes the contact points and before the user pulls up the cane and places it forward again, only the front two legs of the cane remain in contact with the ground. This creates a multiple-stage use of the cane that is less graceful than the use of a standard one-legged cane.
Again, without wishing to be bound by any particular theory, another challenge for multiple-legged canes comes when the ground upon which the user is walking is uneven. If a user is walking on unimproved dirt or rock, a multi-leg cane may have only two or three legs touching the ground. Under such circumstances the user can be surprised by the lack of contact of one leg that creates in an unexpected lack of support and result with the user falling.